Manufacture of artificial materials



June 23, 1936. I w. l. TAYLOR MANUFACTURE OF ARTIF Filed Oct. 26, 1952ICIAL MATERIALS WILL/FM l- T Yl. 0R I YI/ENTOR Patented June 23, 1936UNITED STATES MANUFACTURE OF ARTIFICIAL MATERIALS William Ivan Taylor,Spondon, near Derby, England, assignor to Celanese Corporation ofAmerica, a corporation of Delaware Application Octoberv 26, 1932, SerialNo. 639,612 In Great Britain November 13, 1931 8 Claims. (o1. 18-8) Thisinvention relates to the production of artificial filaments or the likeespecially by the dry or evaporative method, for example, the dryspinning of filaments of cellulose acetate or other derivatives ofcellulose such as other cellulose esters, e. g. cellulose formate,propionate and butyrate, and cellulose ethers, e. g. methyl, ethyl andbutyl cellulose. The invention consists in particular in an improved ormodified apparatus for carrying out the process described in U. S.Patent No. 1,934,618.

According to the prior specification evaporative medium is introducedinto the evaporative atmosphere of a dry spinning cell in the immediatevicinity of the spinning jet for the purpose of controlling the qualityof the filaments extruded from the jet, various forms of apparatus foreffecting this introduction being described in the specification.

The object of the present invention isto provide a simple apparatus bymeans of which the precise position with respect to the jet to which theevaporative atmosphere is injected into the cell, as well as the preciseamount and nature of such injected atmosphere can be regulated inaccordance with the particular requirements of any spinning operationand especially in accordance with the denier and rate of extrusion ofthe filaments.

According to one feature of the invention, a'conduit is arranged in thecell extending over a length covering, measured parallel to thedirection of extrusion, the extremes of the positions in the vicinity ofthe spinning jet at which the evaporative atmosphere, usually air, is tobe injected and a series of apertures is provided in the conduit throughany of which the air to be injected near the spinning jet can bepermitted to escape into the cell. Means are provided for closing suchapertures as are not required for any particular denier or rate ofextrusion, the closure means conveniently comprising apertured registersor caps adapted to be fitted over the apertures. The apertures'areconveniently in the form of slots which direct the air over the wholewidth of the space occupied by the bundle of filaments issuing from thejet. The slots may be formed in a cylindrical, rectangular, or otherconduit of about the same width as the slots so as to'distribute airevenly over the length of each slot. Where caps are used to close suchslot or slots as are not required, the caps may conveniently be carriedby chains or the like which enable them to be sus-' pended in anaccessible position.

Controlof the flow of the air through the conduit, which may either beeffected by the suction usually employed to withdraw air from thespinhing cell or by pressure means adapted to force air through theconduit may be effected by valve or other means in the air connection tothe conduit.

A simple form of control device which has the advantage of enabling anydesired number of such injector devices to be supplied with the samequantity of air, as is required in dry-spinning apparatus in which alarge number of cells are used to produce the same quality of filaments,consists in a screwed plug terminating the air supply pipe for thedevice, the plug being bored with an opening of predetermined size.supply of air to the pipe, the plug is conveniently located in a smallchamber to which the air is supplied, the chamber being provided with acover adapted to be moved to provide access to the plug. The plug may beformed as a nut or provided with a milled edge so that it can be readilyremoved for replacement by a plug having a different sized aperture. Aneedle-valve or other type of control device may, however, be used.

According to a further important feature of the invention, the conduitby means of which air is injected into the cell is made of such materialand is of such configuration within the cell as to bring the air passingthrough the conduit to, or nearly to the temperature of the air in thecell before it is injected. For this purpose the conduit may be arrangedto have a fairly long path within the cell and in addition may be ofsuch form as to offer a large area for the exchange of heat incomparison with its cross section. Thus the conduit may have a flattenedcross section, or it may be corrugated so as to present ridges to theair outside it or it may have to be finned or gilled to presentadditional surface. Or, again, the conduit may be annular in form soas'to present internal as well as external heating surfaces. Furthermeans may be provided for heating the additional air, e; g. a heatingjacket surrounding a coil in the air supply pipe outside the cell.

One or more of the devices according to the invention may be provided ineach spinning cell, e. g. Where the spinning cell contains two spinningjets, two of the devices may be provided and arranged so that theirapertures direct the air towards the jets. In order to provide readyaccess to the jets, the two devices may be placed in two corners of thecell adjacent to the door through which the jets may be reached. In thisway the devices themselves are easilyaccessible for control of theirapertures and yet do'not'prevent the jets For the from being attendedto. If desired the control of the apertures may, however, be arranged tobe effected from outside the cell. The apertured plugs by which theamount of air passing to each device is regulated are preferablyarranged outside the cell.

The device according to the invention may be employed in connection withany suitable form of dry spinning apparatus and in connection with anydesired means for supplying air to or circulating air through thespinning cell. For example, a device or devices may be employed inconnection with cells in which a draw-off device is provided at or nearthe level of the jets to exhaust air from the cell or to produce acurrent of air through the cell. The airintroduced by the device ordevices need not, however, be exhausted wholly at such point, but may beexhausted from some other point or points or partly from one point andpartly from another, and may be used alike in apparatus for upward ordownward spinning and having a counter flow of evaporative medium or aflow in the same direction as the filaments.

The invention will now be described in greater detail with reference tothe accompanying drawing, but it is to be understood that thisdescription is given by way of example only and is in no respectlimitative.

Figure 1 is a side elevation in section of a spinning cell provided withair injection means according to the invention.

Figure 2 is an inverted sectional plan view of Figure 1.

Figure 3 is a rear View of the top of the spinning cell shown in Figure1.

Figures 4 and 5 show two alternative methods of controlling the rate ofair injection, and Figures 6 and 7 show two methods alternative to thatshown in Figure 1 of combining the main air flow through the spinningcell with the air injection of the present invention.

Referring to Figures 1 to 3, a spinning cell I0 is provided with a pipeI l for the supply of spinning solution, the pipe ll leading thespinning solution through a filter candle l2 to a spinning jet l3. Thefilaments l4 extruded from the jet [3 pass down the length of the cellI0, round a guide rod I5, and out of the cell through an aperture l6.After leaving the cell, the filaments 14 pass over a wick I! by means ofwhich a lubricant or other conditioning agent is applied to them, over afeed roller I8, and thence to the guide I9 of a cap spinning device 20by means of which they are twisted, and wound on to a bobbin 20. Acurrent of air enters the cell It] through an inlet pipe 23, passes upthe cell and leaves through a draw-off pipe 24 conveying it to a header25, the rate of flow through the draw-off pipe 24 being adjusted bymeans of a valve 26 and flow gauge means 27. A conduit 30 is arrangedwithin the cell at about the level of the jet I3, the conduit beingprovided with apertures 3i, 32 by means of which air may be injectedinto the cell in the neighbourhood of the jet l3. The conduit 30 isprovided from a pressure header 33 through branch pipes 34 and a controldevice 35 described'in greater detail hereafter.

The apertures 3|, 32, provide means for injecting air at any desiredlevel, and, as will be seen, the two apertures 3| are shown to be closedby means of caps, while the third aperture 32, is open, the slot 37through which the air passes being visible. A gauge 38 is provided inthe header 33 in order to indicate the pressure of the shown in Figure 1enables both jets l3 and both conduits 30 to be reached, the positionsof the conduits not interfering with the accessibility of the jets.

As may be seen in Figure 2, the conduit 36 is of flattened crosssection, in order to present a large surface to the warm air in the cellIE3. In this manner the temperature of the air injected is raisedapproximately to that of the cell. In addition, the conduit 30 may bemade of a material of high heat conductivity, e. g. copper, the wallsbeing as thin as is compatible with sulficiency of strength, in orderfurther to assist the transfer of heat.

In Figure 4 the control device shown at 35 in Figures 1 to 3 isillustrated in detail. The pipe 34 leads the compressed air from theheader 33 into a passage 40 opening into a chamber 45 which is closed bymeans of a cap 46 and a pack ing ring 41. The air passes from thechamber 45 to a passage 49 leading to the conduit 38 shown in Figures 1to 3, but the rate of flow of the air from the chamber 45 is controlledby means of a screwed plug 50 having a precisely drilled orifice 5|. Inorder to vary the rate of flow of the air from the chamber 45, the cap46 is removed and the plug 50 is replaced by a plug having a bore 5| ofdifferent size. In this manner the rate of flow of air into the cell inthe neighbourhood of the jet can be readily and simply controlled.

An alternative control device is shown in Figure 5, wherein the passageof the air from the chamber 45 to the passage 49 is controlled by meansof a needle valve 53 working against a seating 54. The needle valve 53is operated by means of a rod 55 passing through a cover 56 closing thechamber 45, a suitable gland 51 being provided to keep the coverair-tight. The rod 55 screws into the cover 56 at 59 and is controlledby means of a knurled head 60.

In Figure 6, an air injection device according to the invention isillustrated in conjunction with means for passing a co-current ofevaporative atmosphere through the spinning cell. The main current ofair enters the cell through an inlet pipe 6| controlled by means of avalve 62, and leaves near the bottom of the cell by a draw-oil pipe 63controlled by means of a valve 64 and pressure gauge 65, the evaporativemedium leaving in this manner passing into a header 6B. conduit 30,nozzles 3|, 32 and associatedparts are of the type described withreference to Figures 1 to 3. In this figure, the heating eifect of thefiat conduit 40 is supplemented by a preheating device, consisting of acoil 61 in the air supply branch pipe 34, the coil 61 being enclosed ina jacket 68 through which passes a heating fluid by the connections 69,so that the air is heated before reaching the conduit 30.

In Figure 7 air enters by the bottom of the cell as described withreference to Figure 1, and the main current of air leaves the cell bymeans of a draw-off device 10 provided with control means similar tothose described with reference to the draw-off device 24 of Figure 1.Opposite the The nozzles 3|, 32 mounted on the conduit 30 an additionaldraw-01f device 12 is provided, also controlled by means such as thosedescribed in connection with the draw-off device 24, the combination ofthe air injecting means 30, 3|, 32 and the draw-off device 12 inducing acurrent of air to cross the cell below the face of the jet 13.

What I claim and desire to secure by Letters Patent is:-

1. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passing acurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising a conduit arranged within the cellextending over a length covering the extremes of the positions at whichthe additional evaporative atmosphere is to be injected and providedwith a series of apertures through any of which air may be injected asdesired.

2. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passingacurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising a conduit arranged within the cellextending over a length covering the extremes of the positions at whichthe additional evaporative atmosphere is to be injected and providedwith a series of slots through any of which air may be injected asdesired in the form of a wide, flat stream to cover the whole widthoccupied by the bundle of filaments issuing from the jet.

3. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passing acurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising a conduit arranged within the cellextending over a length covering the extremes of the positions at whichthe additional evaporative atmosphere is to be injected and providedwith a series of apertures through any of which air may be injected asdesired, the said conduit being of such length, cross-section andmaterial as to facilitate the transfer of heat from the spinning cell tothe air passing through the conduit.

4. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passing acurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising a control for the additionalevaporative medium in the form of a plug, bored with an opening ofpredetermined size, and readily exchangeable with plugs having openingsof different size, and a conduit for the air passing through said plug,arranged within the cell extending over a length covering the extremesof the positions at which the additional evaporative atmosphere is to beinjected and provided with a series of apertures through any of whichair may be injected as desired.

5. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passing acurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising two conduits disposed in. adjacentcorners of the cell arranged within the cell extending over a lengthcovering the extremes of the positions at which the additionalevaporative atmosphere is to be injected and each provided with a seriesof apertures through any of which air may be injected as desired.

6. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed therein, means for passing acurrent of evaporative medium through the cell, and means forintroducing additional evaporative medium in the neighborhood of thespinning jet, said means comprising means for heating the additionalevaporative medium, a conduit arranged within the cell extending over alength covering the extremes of the positions at which the additionalevaporative atmosphere is to be injected and provided with a series ofapertures through any of which air may be injected as desired.

'7. Apparatus for the production of artificial silk, comprising aspinning cell, a spinning jet disposed at one end thereof, means forintroducing a current of evaporative medium at the end of the cellremote from the spinning jet, means for withdrawing said current at theend of the cell in which the spinning jet is disposed,

and means for introducing additional evaporative medium in theneighborhood of the spinning jet,

said means comprising a conduit arranged within the cell extending overa length covering the extremes of the positions at which the additionalevaporative atmosphere is to be injected and provided with a series ofapertures through any of' which air may be injected as desired.

8. Apparatus for the production of artificial silk, comprising aspinning cell,- a spinning jet disposed at one end thereof, means forintroducing a current of evaporative medium at said end of the cell,means for withdrawing said current at the opposite end of the cell, andmeans for introducing additional evaporative medium in the neighborhoodof the spinning jet, said means comprising a conduit arranged within thecell extending over a length covering the extremes of the positions atwhich the additional evaporative atmosphere is to be injected andprovided with a series of apertures through any of which air may beinjected as desired.

WILLIAM IVAN TAYLOR.

